Function of an enzyme is to lower reaction's activation energy and to increase speed of a reaction, but to make it happen, enzyme and substrate must fit spatially. The shape of an enzyme is essential to make enzyme-substrate complex - if active site of an enzyme doesn't fit to substrate, there won't be a enzyme-catalised reaction.
During phototropism, the plant hormone auxin<span> controls cell elongation.</span>
The Answer is B i just took the test. Enjoy, i also just looked it up on a quizlet. That's another website you can use if it comes up in the search for the question.